NEW HAVEN, Conn., Oct 14, 2004 (United Press International via COMTEX) -- The pigment-producing melanin in blond and redheaded people magnifies ultraviolet rays, heightening the risk of skin cancer in the already susceptible group.
Douglas Brash, principal investigator and professor of therapeutic radiology, genetics and dermatology at Yale School of Medicine said he had been curious why people with dark hair and fair skin were not as vulnerable to skin cancer as fair skinned blondes and redheads.
Melanin filters out UV radiation, but the melanin in hair follicles, particularly in light hair, actually increases the sun damaging effects of UV rays and causes cell death in the hair follicle, Brash said.
Using mice engineered with pigmentation for yellow or black hair, as well as albino mice with no pigment at all, researchers irradiated the mice with UV rays that are about the same as what reaches humans.
The cell death was concentrated around the hair follicles, which are the only location of melanin in mice. Dying cells were particularly pronounced in the yellow-haired mice and was absent in albinos.
Copyright 2004 by United Press International.